Archive for April, 2010

I’m a visual and hands-on kind of person and as such, I tend to make use of images in my blog posts. Flickr is an online provider that hosts images free of charge which saves me bandwidth costs and delivers content to blog readers quickly. In a sense, they are a cloud provider. Flickr Manager is a WordPress plugin that allows me to efficiently browse and insert Flickr images from the comfort of my WordPress blog editor, among other things.

Several months ago, the Flickr Manager overlay stopped working correctly. The overlay was no longer inserting images into my blog posts as I had been instructing it to. I filed a bug (#144) with the author as follows:

What steps will reproduce the problem?

1. Create a new blog post or page

2. Click on the “Add Flickr Photo” icon.

3. In the overlay under “My Photos” tab, click on a photo to insert.

4. In the summary overlay page, once the photo is selected in the overlay, click the “Insert into Post” button.

5. The summary overlay page for the photo returns and no photo is inserted into the blog post.

What is the expected output? What do you see instead?

I expect the photo to be inserted into the blog post and the Flickr overlay should close. Instead, the overlay stays open as if nothing has happened. The same thing happens if I check the box “Close on insert” on the overlay page.

What version of the plugin are you using? Which version of WordPress? Flickr Manager version 2.3. WordPress 2.9.2

Please provide a link to your photo gallery, or the page that has the bug: My Flickr Photostream is at http://www.flickr.com/photos/31838982@N08/

Which hosting provider are you on? What version of Apache or IIS are you using? Self hosted out of my home. Windows Server 2003, IIS 6

Please provide any additional information below.

This plugin was working fine for the first several months but after a while it stopped inserting photos. I can’t associate the breakage with any sort of upgrade such as a WordPress upgrade, plugin upgrade, or theme change. Any help would be appreciated.

Browsing my Flickr album, grabbing URLs for images, and inserting them into my blog posts manually is a painful process involving multiple browser windows. I was really missing the functionality of Flickr Manager. It was deterring me from writing blog posts which I knew I wanted to incorporate images. Using Google, I was able to locate a few others who had stumbled onto this problem, but I was unable to find any solutions.

I turned to Twitter, a universe of technical expertise, among many other things I’m sure. Kelly Culwell and Grant Bivens, Solution Architect and Web Developer resepectively of Interworks, Inc., answered the call. I had spoken with Kelly off and on the past few months regarding VMware topics. They quickly turned me on to this page which described fix. All I had to do was modify three of the plugin files, removing any occurrance of the @ symbol. Grant described the problem as a JavaScript selector the author used which has since been depreciated.

Happy days once again, the solution worked! These guys wanted nothing in return but their kind offer to help and quick solution definitely deserves mention. My faith in humanity has been partially restored thanks to these gentlemen. Kudos and great job!

The vSphere 4.0 Hardening Guide, a collaborative effort which has been under development for several months with a few interim beta distributions, has been finalized and released. The document is presented in a flexible format in that a few different levels of hardening can be used as low to high risk boundaries. The user then ultimately decides on the appropriate hardening level depending on the level of risk the user is comfortable with assuming.The guide covers several key VMware Virtual Infrastructure areas. To quote VMware’s announcement:

Overall, there are more than 100 guidelines, with the following major sections:

Introduction

Virtual Machines

Host (both ESXi and ESX)

vNetwork

vCenter

Console OS (for ESX only)

If you’ve recently deployed vSphere or if you are about to, check out these hardening guides to help secure your datacenter. You can’t beat the price – free!

I few weeks ago, I came across a networking issue with VMware ESX(i) 4.0 Update 1. The issue is that configuring a vSwitch or Portgroup for Failback: No doesn’t work as expected in conjunction with a Network Failover Detection type of Link Status Only.

For the simplest of examples:

Configure a vSwitch with 2 VMNIC uplinks with both NICs in an Active configuration. I’ll refer to the uplinks as VMNIC0 and VMNIC1.

Configure the vSwitch and/or a Portgroup on the vSwitch for Failback: No.

Create a few test VMs with outbound TCP/IP through the vSwitch.

Power on the VMs and begin a constant ping to each of the VMs from the network on the far side of the vSwitch.

Pull the network cable from VMNIC0. You should see little to no network connectivity loss on the constant pings.

With VMNIC0 failed, at this point, all network traffic is riding over VMNIC1. When VMNIC0 is recovered, the expected behavior with No Failback is that all traffic will continue to traverse VMNIC1.

Now provide VMNIC0 with a link signal by connecting it to a switch port which has no route to the physical network. For example, simply connect VMNIC0 to a portable Netgear or Linksys switch.

What you should see now is that at least one of the VMs is unpingable. It has lost network connectivity because ESX has actually failed its network path back to VMNIC0. In the failback mechanism, VMware appears to balance the traffic evenly. In a 2 VM test, 1 VM will fail back to the recovered VMNIC. In a 4 VM test, 2 VMs will fail back to the recovered VMNIC. Etc.

The impact spreads to any traffic being supported by the vSwitch, not just VM networking. Thus, the impact includes Service Console, Management Network, IP based storage, VMotion, and FT. Scope of the bug includes both the standard vSwitch as well as the vSphere Distributed Switch (vDS).

Based on the following VMTN forum thread, it would appear this bug has existed since August of 2008. Unfortunately, documentation of the bug never made it to VMware support:

You may be asking yourself at this point, well who really cares? At the very least, we have on our hands a feature which does not work as documented on page 41 of the following manual: http://www.vmware.com/pdf/vsphere4/r40_u1/vsp_40_u1_esxi_server_config.pdf. Organizations which have made a design decision for no failback have done so for a reason and rely on the feature to work as it is documented.

Why would my VMNIC ever come up with no routing capabilities to the physical network? Granted, my test was simplistic in nature and doesn’t likely represent an actual datacenter design but the purpose was merely to point out to folks that the problem does exist. The issue actually does present a real world problem for at least one environment I’ve seen. Consider an HP C-class blade chassis fitted with redundant 10GbE Flex10 Ethernet modules. Upstream to the Flex10 modules are Cisco Nexus 5k switches and then Nexus 7k switches.

When a Flex10 module fails and is recovered (say for instance it was rebooted – which you can test yourself if you have one), it has an unfortunate habit of bringing up the blade facing network ports (in this case, VMNIC0 labeled 1 in the diagram) up to 20 seconds before a link is established with the upstream Cisco Nexus 5k (labeled 2 in the diagram) which grants network routing to other infrastructure components. So what happens here? VMNIC0 shows a link and ESX fails back traffic to it up to 20 seconds before the link to the Nexus 5k is established. There is a network outage for Service Console, Management Network, IP based storage, VMotion, and FT. Perhaps some may say they can tolerate this much of an outage for their VM traffic, but most people I have talked to say even an outage of 2 or more seconds is unacceptable. And what about IP based storage? Can you afford the 20 second latency? What about Management Network and Service Console? Think HA and isolation response impact. VMs shutting down as a result. Etc. It’s a nasty chain of events. In such a case, a decision can be made to enable no failback as a policy on the vSwith and Portgroups. However, due to the VMware bug, this doesn’t work. Some day you may experience an outage which you did not expect.

As pointed out in the VMTN forum thread above, there is a workaround which I have tested and does work: Force at least one VMNIC to act as Standby. This is not by VMware design, it just happens to make the no failback behavior work correctly. The impact with this design decision is of course that now one VMNIC stands idle and there are no load balancing opportunities over this VMNIC. In addition, with no failback enabled, network traffic will tend to become polarized to one side again impacting network load balancing.

An SR has been opened with VMware on this issue. They have confirmed it is a bug and will be working to resolve the issue in a future patch or release.

Update 4/27/10: The no failback issue has been root-caused by VMware and a fix has been constructed and is being tested. It will be triaged for a future release.

SANTA CLARA, CA – April 6, 2010 – Data Robotics, Inc., the company that delivers the best data storage experience, today introduced Drobo FS, a breakthrough Drobo designed for simple, expandable file sharing. By providing network file sharing capabilities along with automated data protection, the Drobo FS greatly simplifies shared storage for connected home, home office and small office users. Based on the revolutionary BeyondRAID technology and a flexible platform for adding features and capacity as needed, the Drobo FS can quickly and easily be customized and scaled to meet current or future storage requirements.

“Adding to Data Robotics’ offering of self-managing storage solutions, the Drobo FS offers users the ability to share data between computers quickly and easily,” said Liz Conner, research analyst for IDC’s storage systems and personal storage device & systems. “More than ever before, home users and small offices want to access and share a growing amount of data, but they don’t need a large, expensive system that requires specific expertise or extensive management. With the Drobo FS, Data Robotics addresses a need for which many Drobo users have been looking forward.”

“We have been using Drobo solutions to store our data for almost three years and continue to be happy with their performance and simplicity. With four computers on our network, we also needed a solution that would allow us to share data between users. Typical shared storage devices were complicated or too expensive, so we’re thrilled that Data Robotics has created the Drobo FS,” said Seth Resnick, Co-Founder at D65. “Drobo FS comes with just the functionality we need, so it is easy to use while still providing the automated data protection that comes with BeyondRAID. The additional DroboApps allow us to add new features as we need them, which is really unique.”

Drobo FS Features and Benefits

Plug In and Share – The Drobo FS connects directly to any Gigabit Ethernet network for a true plug in and share set-up experience. Supports standard data transfer protocols including Apple File Protocol (AFP) and Microsoft Common Internet File System (CIFS).

5-Drive Capacity and Instant Expansion to 10TB and Beyond – Customers with growing storage requirements can easily add data capacity by simply inserting a new hard drive or replacing the smallest drive with a larger one, even when all five drive bays are full. With Drobo FS, expansion is automatic, instantaneous, and access to data is always maintained.

Single- and Dual-Drive Redundancy – The Drobo FS dual drive redundancy option protects against the simultaneous failure of up to two hard drives. Customers can engage this option with a single click without ever losing access to their data.

Self-Healing Technology – With BeyondRAID, the Drobo FS continually examines data blocks and sectors on each drive to flag potential issues. The preemptive “scrubbing” helps ensure data is being written only to healthy drive areas and automatically keeps data in the safest state possible – even when a drive fails.

Customizable Storage –Utilizing the growing library of DroboApps, including media and web applications, users can customize the Drobo FS to further enhance their sharing experience.

“This is the decade of being connected, no matter where you are or what kind of data you are storing. The Drobo FS was designed to best serve the needs of our customers with file sharing needs – from small offices and home offices to connected homes. By reducing the complexity of data sharing and providing a truly flexible platform for adding capacity and features, the Drobo FS is ideal for users that have the need to share ever increasing amounts of data,” said Tom Buiocchi, CEO of Data Robotics.

Pricing and Availability Drobo FS is currently available at a starting price of $699 MSRP, with multiple configurations to $1,449 for a 10TB (5x 2TB drives) bundle. Drobo FS is available now from authorized partners worldwide and on www.drobostore.com. To learn more about Drobo FS, please visit www.drobo.com/drobo-fs.

About Data Robotics
Data Robotics, Inc., the company that delivers the best storage experience ever, develops automated storage products designed to ensure data is always protected, accessible, and simple to manage. The award-winning Drobo storage arrays are the first to provide the protection of traditional RAID without the complexity. The revolutionary BeyondRAID technology frees users from making the difficult and confining choice of “Which RAID level to deploy?” by providing an unprecedented combination of advanced features and automation, including single- and dual-drive redundancy, instant expansion, self-monitoring, data awareness, self-healing, and an easy-to-understand visual status and alert panel. For more information, visit Data Robotics at www.datarobotics.com.

I spent some time with Data Robotics listening about the Drobo FS in addition to their existing storage offerings. Here are some of the things I learned about the FS:

FS = File Sharing

True plug and play setup

Drobo FS is automatically discovered on PC and Mac

Gigabit Ethernet

Up to 5 hot-swappable drives

Single or dual drive redundancy

All the magic and ease found in the Drobo S (such as BeyondRAID) is now implemented into a network storage device (such as DroboApps)

Adds network based storage while removing the complexity of managing RAID

Target uses:

Shared file storage

Network backup

Private cloud (IP storage accessible via the internet)

Add additional functionality to the Drobo FS via DroboApps

Bolt on applications are accessible from Drobo Share page

Backed by a developer community

DroboApps are free; no plans to charge fees

Apps are small, 1MB or less in size, and stored on reserved space of the Drobo FS

VMware Administrators who use VMware Update Manager (and I highly recommend its use), will have noticed that 10 new patches were released for VMware vSphere on 4/1/2010. A few for the Cisco Nexus 1000V VEM, and the remainder of the updates are for ESX(i) 4.0.

Two of the patches which I’d like to highlight, ESX400-201003401-BG and ESXi400-201003401-BG, make some required changes to the virtual infrastructure which you should be aware of. The .VMDK file naming convention, introduced originally in ESX 2.x, is being retired in favor of the original naming convention .DSK which existed prior to ESX 2.x. The reasoning for this is not yet known but as the saying goes, “You can’t make an omelette without breaking a few eggs.” So suck it up; it’s not all about you.

How does this affect you? The impacts will vary depending on your role with VMware Virtual Infrastructure:

VI Administrators will need to update any scripts which may be impacted.

3rd party tool vendors will need to update any code which references .VMDK files.

Book authors would be advised to perform a mass “find and replace” before their next printing. For tactical advice on how to do this, speak to Scott Herold or Ron Oglesby as they have experience in this. As for books and articles already published on VMware disk technologies using the .VMDK naming scheme, refer to the omelette statement above.

Lab Manager and View environments are not yet compatible with the file naming convention change. An updated release for each of these products should be available by Q4 this year, Q1 2011 at the latest.

I am completely in favor of this change. I never did adapt fully to the migration from .DSK to .VMDK, so this will be just like old times for me. We need more radical ideas like this to break the chains of complacency. From a sales perspective, VMware can totally pitch changes like these as innovation which keeps them several steps ahead of their competitors. So what’s next? Inside sources tell me HA naming is going back to its roots: Hello Dynamic Availability Service!